Stocks of unused, fresh HEU fuel also become a liability when a research reactor shuts down. Fresh HEU fuel - material not yet used in a nuclear research reactor - is low in radioactivity. This makes it far easier for a thief to transport than the highly radioactive spent fuel wastes.
"What we are talking about is weapons-grade material that is not self-protecting - material that is not so radioactive that people can't just pick it up and carry it away," Mr. Krass said.
The IAEA is helping Member States to transfer unwanted fresh HEU stocks back to the country that supplied it. In August 2002 it helped transfer 45 kilograms (enough fissile material to make two nuclear bombs) from Serbia and Montenegro back to Russia, to be blended down to low-enriched uranium (LEU) that cannot be used in a nuclear weapon. Most recently it assisted Libya in March 2004. In December 2003 it assisted Bulgaria and in September 2003, Romania. More return shipments are planned in other countries.
Currently about 130 research reactors around the world still run on weapons-grade HEU. In an article "A Safer World" published in The Economist, IAEA Director General Mohamed ElBaradei called for an end to trade in HEU.
"Existing facilities around the world that use high-enriched uranium applications - for example, to produce medical radioisotopes - should continue, gradually but irreversibly, to be converted to low-enriched processes."
The Agency is helping countries do exactly that. It actively supports them to convert their research reactors from burning HEU to LEU. In conjunction with the US "Reduced Enrichment for Research and Test Reactors" (RERTR) programme the Agency is helping to reduce and eventually eliminate international commerce in HEU for research reactors.
So far 29 reactors have been fully converted to LEU and a further seven are in the process of converting. Countries seeking IAEA assistance include Brazil and Romania.
Safety and security is a twin challenge of rising proportions as more and more research reactors are shut down or decommissioned this decade. The IAEA stands ready to help but with limited resources improvements come slowly, says Mr. Ritchie. Signs fortunately are pointing to more international support and co-operation in months and years ahead.
Kirstie Hansen, IAEA Division of Public Information. For more information see the feature series on the IAEA web site www.iaea.org.